The major objective of this project is to investigate the role of vitamin E in cell culture. Recent work from this and other laboratories had indicated that cells in culture are metabolically very dissimilar from their tissues of origin. Preliminary evidence indicates that this is largely due to the medium in which the cells are grown. Thus, a primary objective will be to develop a cultural environment which will yield cells metabolically similar to in vivo tissues. This will be approached with the aim of decreasing the ratio of glycolytac to respiratory pathways by studying such factors as pH, carbon source, and gas concentrations. The effects of these alterations will be monitored by measuring the effect of oxygen in decreasing the production of lactate from glucose, the so-called Pasteur effect. Past work from this laboratory has already indicated that this approach can yield data showing growth effects in some cell strains. Since tissues are not equally affected by a vitamin E-deficiency in vivo, a survey of different cell types will be made to determine if some generalizatio can be reached about the relationship of the metabolic potential of cells and their requirement for vitamin E. Concurrently, with a cell strain for which we have already established a vitamin E. requirement, we shall investigate the role of the vitamin action. We shall study the effect of tocopherol on the synthesis of heme-containing enzymes and on the levels of enzymes involved in heme synthesis. With the use of radioactive tracers we shall the effect of unsaturated fatty acids on the binding of vitamin E. to the cell membrane and the converse experiment will also be done. To test the effect of tocopherol on the function of the membrane, transport studies of a sugar, an amino acid, and rubidium will be made The relation of tese effectss to theories of vitamin E action such as the antioxidant function and more direct roles in intermidiate metabolism will be evaluated. Recent studies have now clearly shown a growth - promoting effect of cholesterol in conjunction with vitamin E and unsaturated fatty acids. The cholesterol of the vitamin E effect and cell - growth will be investigated in greater detail.